With the CSi BMW really turned out one of their finest engines. A touch more tuning by Bosch Motronic expert Jim Conforti yields just a little more punch from the big V12. Conforti altered the fuel and ignition mapping to take advantage of premium fuel (91+ octane). Although the 850CSi is required to run "premium" anyway, it is not optimized for it. Changing these settings results in more power and a smoother-running engine.

Click here for a dyno chart!
 

Horsepower Gain	+ 12 @ 5300 RPM
Torque Gain	+ 20 @ 4000 RPM
New Rev Limit	EML controls redline